1 //===-- llvm/BinaryFormat/XCOFF.h - The XCOFF file format -------*- C++/-*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file defines manifest constants for the XCOFF object file format.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_BINARYFORMAT_XCOFF_H
14 #define LLVM_BINARYFORMAT_XCOFF_H
15 
16 #include <stddef.h>
17 #include <stdint.h>
18 
19 namespace llvm {
20 class StringRef;
21 template <unsigned> class SmallString;
22 template <typename T> class Expected;
23 
24 namespace XCOFF {
25 
26 // Constants used in the XCOFF definition.
27 
28 constexpr size_t FileNamePadSize = 6;
29 constexpr size_t NameSize = 8;
30 constexpr size_t FileHeaderSize32 = 20;
31 constexpr size_t FileHeaderSize64 = 24;
32 constexpr size_t SectionHeaderSize32 = 40;
33 constexpr size_t SectionHeaderSize64 = 72;
34 constexpr size_t SymbolTableEntrySize = 18;
35 constexpr size_t RelocationSerializationSize32 = 10;
36 constexpr size_t RelocationSerializationSize64 = 14;
37 constexpr uint16_t RelocOverflow = 65535;
38 constexpr uint8_t AllocRegNo = 31;
39 
40 enum ReservedSectionNum : int16_t { N_DEBUG = -2, N_ABS = -1, N_UNDEF = 0 };
41 
42 enum MagicNumber : uint16_t { XCOFF32 = 0x01DF, XCOFF64 = 0x01F7 };
43 
44 // x_smclas field of x_csect from system header: /usr/include/syms.h
45 /// Storage Mapping Class definitions.
46 enum StorageMappingClass : uint8_t {
47   //     READ ONLY CLASSES
48   XMC_PR = 0,      ///< Program Code
49   XMC_RO = 1,      ///< Read Only Constant
50   XMC_DB = 2,      ///< Debug Dictionary Table
51   XMC_GL = 6,      ///< Global Linkage (Interfile Interface Code)
52   XMC_XO = 7,      ///< Extended Operation (Pseudo Machine Instruction)
53   XMC_SV = 8,      ///< Supervisor Call (32-bit process only)
54   XMC_SV64 = 17,   ///< Supervisor Call for 64-bit process
55   XMC_SV3264 = 18, ///< Supervisor Call for both 32- and 64-bit processes
56   XMC_TI = 12,     ///< Traceback Index csect
57   XMC_TB = 13,     ///< Traceback Table csect
58 
59   //       READ WRITE CLASSES
60   XMC_RW = 5,   ///< Read Write Data
61   XMC_TC0 = 15, ///< TOC Anchor for TOC Addressability
62   XMC_TC = 3,   ///< General TOC item
63   XMC_TD = 16,  ///< Scalar data item in the TOC
64   XMC_DS = 10,  ///< Descriptor csect
65   XMC_UA = 4,   ///< Unclassified - Treated as Read Write
66   XMC_BS = 9,   ///< BSS class (uninitialized static internal)
67   XMC_UC = 11,  ///< Un-named Fortran Common
68 
69   XMC_TL = 20, ///< Initialized thread-local variable
70   XMC_UL = 21, ///< Uninitialized thread-local variable
71   XMC_TE = 22  ///< Symbol mapped at the end of TOC
72 };
73 
74 // Flags for defining the section type. Masks for use with the (signed, 32-bit)
75 // s_flags field of the section header structure, selecting for values in the
76 // lower 16 bits. Defined in the system header `scnhdr.h`.
77 enum SectionTypeFlags : int32_t {
78   STYP_PAD = 0x0008,
79   STYP_DWARF = 0x0010,
80   STYP_TEXT = 0x0020,
81   STYP_DATA = 0x0040,
82   STYP_BSS = 0x0080,
83   STYP_EXCEPT = 0x0100,
84   STYP_INFO = 0x0200,
85   STYP_TDATA = 0x0400,
86   STYP_TBSS = 0x0800,
87   STYP_LOADER = 0x1000,
88   STYP_DEBUG = 0x2000,
89   STYP_TYPCHK = 0x4000,
90   STYP_OVRFLO = 0x8000
91 };
92 
93 /// Values for defining the section subtype of sections of type STYP_DWARF as
94 /// they would appear in the (signed, 32-bit) s_flags field of the section
95 /// header structure, contributing to the 16 most significant bits. Defined in
96 /// the system header `scnhdr.h`.
97 enum DwarfSectionSubtypeFlags : int32_t {
98   SSUBTYP_DWINFO = 0x1'0000,  ///< DWARF info section
99   SSUBTYP_DWLINE = 0x2'0000,  ///< DWARF line section
100   SSUBTYP_DWPBNMS = 0x3'0000, ///< DWARF pubnames section
101   SSUBTYP_DWPBTYP = 0x4'0000, ///< DWARF pubtypes section
102   SSUBTYP_DWARNGE = 0x5'0000, ///< DWARF aranges section
103   SSUBTYP_DWABREV = 0x6'0000, ///< DWARF abbrev section
104   SSUBTYP_DWSTR = 0x7'0000,   ///< DWARF str section
105   SSUBTYP_DWRNGES = 0x8'0000, ///< DWARF ranges section
106   SSUBTYP_DWLOC = 0x9'0000,   ///< DWARF loc section
107   SSUBTYP_DWFRAME = 0xA'0000, ///< DWARF frame section
108   SSUBTYP_DWMAC = 0xB'0000    ///< DWARF macinfo section
109 };
110 
111 // STORAGE CLASSES, n_sclass field of syment.
112 // The values come from `storclass.h` and `dbxstclass.h`.
113 enum StorageClass : uint8_t {
114   // Storage classes used for symbolic debugging symbols.
115   C_FILE = 103,  // File name
116   C_BINCL = 108, // Beginning of include file
117   C_EINCL = 109, // Ending of include file
118   C_GSYM = 128,  // Global variable
119   C_STSYM = 133, // Statically allocated symbol
120   C_BCOMM = 135, // Beginning of common block
121   C_ECOMM = 137, // End of common block
122   C_ENTRY = 141, // Alternate entry
123   C_BSTAT = 143, // Beginning of static block
124   C_ESTAT = 144, // End of static block
125   C_GTLS = 145,  // Global thread-local variable
126   C_STTLS = 146, // Static thread-local variable
127 
128   // Storage classes used for DWARF symbols.
129   C_DWARF = 112, // DWARF section symbol
130 
131   // Storage classes used for absolute symbols.
132   C_LSYM = 129,  // Automatic variable allocated on stack
133   C_PSYM = 130,  // Argument to subroutine allocated on stack
134   C_RSYM = 131,  // Register variable
135   C_RPSYM = 132, // Argument to function or procedure stored in register
136   C_ECOML = 136, // Local member of common block
137   C_FUN = 142,   // Function or procedure
138 
139   // Storage classes used for undefined external symbols or
140   // symbols of general sections.
141   C_EXT = 2,       // External symbol
142   C_WEAKEXT = 111, // Weak external symbol
143 
144   // Storage classes used for symbols of general sections.
145   C_NULL = 0,
146   C_STAT = 3,     // Static
147   C_BLOCK = 100,  // ".bb" or ".eb"
148   C_FCN = 101,    // ".bf" or ".ef"
149   C_HIDEXT = 107, // Un-named external symbol
150   C_INFO = 110,   // Comment string in .info section
151   C_DECL = 140,   // Declaration of object (type)
152 
153   // Storage classes - Obsolete/Undocumented.
154   C_AUTO = 1,     // Automatic variable
155   C_REG = 4,      // Register variable
156   C_EXTDEF = 5,   // External definition
157   C_LABEL = 6,    // Label
158   C_ULABEL = 7,   // Undefined label
159   C_MOS = 8,      // Member of structure
160   C_ARG = 9,      // Function argument
161   C_STRTAG = 10,  // Structure tag
162   C_MOU = 11,     // Member of union
163   C_UNTAG = 12,   // Union tag
164   C_TPDEF = 13,   // Type definition
165   C_USTATIC = 14, // Undefined static
166   C_ENTAG = 15,   // Enumeration tag
167   C_MOE = 16,     // Member of enumeration
168   C_REGPARM = 17, // Register parameter
169   C_FIELD = 18,   // Bit field
170   C_EOS = 102,    // End of structure
171   C_LINE = 104,
172   C_ALIAS = 105,  // Duplicate tag
173   C_HIDDEN = 106, // Special storage class for external
174   C_EFCN = 255,   // Physical end of function
175 
176   // Storage classes - reserved
177   C_TCSYM = 134 // Reserved
178 };
179 
180 // Flags for defining the symbol type. Values to be encoded into the lower 3
181 // bits of the (unsigned, 8-bit) x_smtyp field of csect auxiliary symbol table
182 // entries. Defined in the system header `syms.h`.
183 enum SymbolType : uint8_t {
184   XTY_ER = 0, ///< External reference.
185   XTY_SD = 1, ///< Csect definition for initialized storage.
186   XTY_LD = 2, ///< Label definition.
187               ///< Defines an entry point to an initialized csect.
188   XTY_CM = 3  ///< Common csect definition. For uninitialized storage.
189 };
190 
191 /// Values for visibility as they would appear when encoded in the high 4 bits
192 /// of the 16-bit unsigned n_type field of symbol table entries. Valid for
193 /// 32-bit XCOFF only when the vstamp in the auxiliary header is greater than 1.
194 enum VisibilityType : uint16_t {
195   SYM_V_UNSPECIFIED = 0x0000,
196   SYM_V_INTERNAL = 0x1000,
197   SYM_V_HIDDEN = 0x2000,
198   SYM_V_PROTECTED = 0x3000,
199   SYM_V_EXPORTED = 0x4000
200 };
201 
202 // Relocation types, defined in `/usr/include/reloc.h`.
203 enum RelocationType : uint8_t {
204   R_POS = 0x00, ///< Positive relocation. Provides the address of the referenced
205                 ///< symbol.
206   R_RL = 0x0c,  ///< Positive indirect load relocation. Modifiable instruction.
207   R_RLA = 0x0d, ///< Positive load address relocation. Modifiable instruction.
208 
209   R_NEG = 0x01, ///< Negative relocation. Provides the negative of the address
210                 ///< of the referenced symbol.
211   R_REL = 0x02, ///< Relative to self relocation. Provides a displacement value
212                 ///< between the address of the referenced symbol and the
213                 ///< address being relocated.
214 
215   R_TOC = 0x03, ///< Relative to the TOC relocation. Provides a displacement
216                 ///< that is the difference between the address of the
217                 ///< referenced symbol and the TOC anchor csect.
218   R_TRL = 0x12, ///< TOC relative indirect load relocation. Similar to R_TOC,
219                 ///< but not modifiable instruction.
220 
221   R_TRLA =
222       0x13, ///< Relative to the TOC or to the thread-local storage base
223             ///< relocation. Compilers are not permitted to generate this
224             ///< relocation type. It is the result of a reversible
225             ///< transformation by the linker of an R_TOC relation that turned a
226             ///< load instruction into an add-immediate instruction.
227 
228   R_GL = 0x05, ///< Global linkage-external TOC address relocation. Provides the
229                ///< address of the external TOC associated with a defined
230                ///< external symbol.
231   R_TCL = 0x06, ///< Local object TOC address relocation. Provides the address
232                 ///< of the local TOC entry of a defined external symbol.
233 
234   R_REF = 0x0f, ///< A non-relocating relocation. Used to prevent the binder
235                 ///< from garbage collecting a csect (such as code used for
236                 ///< dynamic initialization of non-local statics) for which
237                 ///< another csect has an implicit dependency.
238 
239   R_BA = 0x08, ///< Branch absolute relocation. Provides the address of the
240                ///< referenced symbol. References a non-modifiable instruction.
241   R_BR = 0x0a, ///< Branch relative to self relocation. Provides the
242                ///< displacement that is the difference between the address of
243                ///< the referenced symbol and the address of the referenced
244                ///< branch instruction. References a non-modifiable instruction.
245   R_RBA = 0x18, ///< Branch absolute relocation. Similar to R_BA but
246                 ///< references a modifiable instruction.
247   R_RBR = 0x1a, ///< Branch relative to self relocation. Similar to the R_BR
248                 ///< relocation type, but references a modifiable instruction.
249 
250   R_TLS = 0x20,    ///< General-dynamic reference to TLS symbol.
251   R_TLS_IE = 0x21, ///< Initial-exec reference to TLS symbol.
252   R_TLS_LD = 0x22, ///< Local-dynamic reference to TLS symbol.
253   R_TLS_LE = 0x23, ///< Local-exec reference to TLS symbol.
254   R_TLSM = 0x24,  ///< Module reference to TLS. Provides a handle for the module
255                   ///< containing the referenced symbol.
256   R_TLSML = 0x25, ///< Module reference to the local TLS storage.
257 
258   R_TOCU = 0x30, ///< Relative to TOC upper. Specifies the high-order 16 bits of
259                  ///< a large code model TOC-relative relocation.
260   R_TOCL = 0x31 ///< Relative to TOC lower. Specifies the low-order 16 bits of a
261                 ///< large code model TOC-relative relocation.
262 };
263 
264 enum CFileStringType : uint8_t {
265   XFT_FN = 0,  ///< Specifies the source-file name.
266   XFT_CT = 1,  ///< Specifies the compiler time stamp.
267   XFT_CV = 2,  ///< Specifies the compiler version number.
268   XFT_CD = 128 ///< Specifies compiler-defined information.
269 };
270 
271 enum CFileLangId : uint8_t {
272   TB_C = 0,        ///< C language.
273   TB_CPLUSPLUS = 9 ///< C++ language.
274 };
275 
276 enum CFileCpuId : uint8_t {
277   TCPU_PPC64 = 2, ///< PowerPC common architecture 64-bit mode.
278   TCPU_COM = 3,   ///< POWER and PowerPC architecture common.
279   TCPU_970 = 19   ///< PPC970 - PowerPC 64-bit architecture.
280 };
281 
282 enum SymbolAuxType : uint8_t {
283   AUX_EXCEPT = 255, ///< Identifies an exception auxiliary entry.
284   AUX_FCN = 254,    ///< Identifies a function auxiliary entry.
285   AUX_SYM = 253,    ///< Identifies a symbol auxiliary entry.
286   AUX_FILE = 252,   ///< Identifies a file auxiliary entry.
287   AUX_CSECT = 251,  ///< Identifies a csect auxiliary entry.
288   AUX_SECT = 250    ///< Identifies a SECT auxiliary entry.
289 };                  // 64-bit XCOFF file only.
290 
291 StringRef getMappingClassString(XCOFF::StorageMappingClass SMC);
292 StringRef getRelocationTypeString(XCOFF::RelocationType Type);
293 Expected<SmallString<32>> parseParmsType(uint32_t Value, unsigned FixedParmsNum,
294                                          unsigned FloatingParmsNum);
295 Expected<SmallString<32>> parseParmsTypeWithVecInfo(uint32_t Value,
296                                                     unsigned FixedParmsNum,
297                                                     unsigned FloatingParmsNum,
298                                                     unsigned VectorParmsNum);
299 Expected<SmallString<32>> parseVectorParmsType(uint32_t Value,
300                                                unsigned ParmsNum);
301 
302 struct TracebackTable {
303   enum LanguageID : uint8_t {
304     C,
305     Fortran,
306     Pascal,
307     Ada,
308     PL1,
309     Basic,
310     Lisp,
311     Cobol,
312     Modula2,
313     CPlusPlus,
314     Rpg,
315     PL8,
316     PLIX = PL8,
317     Assembly,
318     Java,
319     ObjectiveC
320   };
321   // Byte 1
322   static constexpr uint32_t VersionMask = 0xFF00'0000;
323   static constexpr uint8_t VersionShift = 24;
324 
325   // Byte 2
326   static constexpr uint32_t LanguageIdMask = 0x00FF'0000;
327   static constexpr uint8_t LanguageIdShift = 16;
328 
329   // Byte 3
330   static constexpr uint32_t IsGlobaLinkageMask = 0x0000'8000;
331   static constexpr uint32_t IsOutOfLineEpilogOrPrologueMask = 0x0000'4000;
332   static constexpr uint32_t HasTraceBackTableOffsetMask = 0x0000'2000;
333   static constexpr uint32_t IsInternalProcedureMask = 0x0000'1000;
334   static constexpr uint32_t HasControlledStorageMask = 0x0000'0800;
335   static constexpr uint32_t IsTOClessMask = 0x0000'0400;
336   static constexpr uint32_t IsFloatingPointPresentMask = 0x0000'0200;
337   static constexpr uint32_t IsFloatingPointOperationLogOrAbortEnabledMask =
338       0x0000'0100;
339 
340   // Byte 4
341   static constexpr uint32_t IsInterruptHandlerMask = 0x0000'0080;
342   static constexpr uint32_t IsFunctionNamePresentMask = 0x0000'0040;
343   static constexpr uint32_t IsAllocaUsedMask = 0x0000'0020;
344   static constexpr uint32_t OnConditionDirectiveMask = 0x0000'001C;
345   static constexpr uint32_t IsCRSavedMask = 0x0000'0002;
346   static constexpr uint32_t IsLRSavedMask = 0x0000'0001;
347   static constexpr uint8_t OnConditionDirectiveShift = 2;
348 
349   // Byte 5
350   static constexpr uint32_t IsBackChainStoredMask = 0x8000'0000;
351   static constexpr uint32_t IsFixupMask = 0x4000'0000;
352   static constexpr uint32_t FPRSavedMask = 0x3F00'0000;
353   static constexpr uint32_t FPRSavedShift = 24;
354 
355   // Byte 6
356   static constexpr uint32_t HasExtensionTableMask = 0x0080'0000;
357   static constexpr uint32_t HasVectorInfoMask = 0x0040'0000;
358   static constexpr uint32_t GPRSavedMask = 0x003F'0000;
359   static constexpr uint32_t GPRSavedShift = 16;
360 
361   // Byte 7
362   static constexpr uint32_t NumberOfFixedParmsMask = 0x0000'FF00;
363   static constexpr uint8_t NumberOfFixedParmsShift = 8;
364 
365   // Byte 8
366   static constexpr uint32_t NumberOfFloatingPointParmsMask = 0x0000'00FE;
367   static constexpr uint32_t HasParmsOnStackMask = 0x0000'0001;
368   static constexpr uint8_t NumberOfFloatingPointParmsShift = 1;
369 
370   // Masks to select leftmost bits for decoding parameter type information.
371   // Bit to use when vector info is not presented.
372   static constexpr uint32_t ParmTypeIsFloatingBit = 0x8000'0000;
373   static constexpr uint32_t ParmTypeFloatingIsDoubleBit = 0x4000'0000;
374   // Bits to use when vector info is presented.
375   static constexpr uint32_t ParmTypeIsFixedBits = 0x0000'0000;
376   static constexpr uint32_t ParmTypeIsVectorBits = 0x4000'0000;
377   static constexpr uint32_t ParmTypeIsFloatingBits = 0x8000'0000;
378   static constexpr uint32_t ParmTypeIsDoubleBits = 0xC000'0000;
379   static constexpr uint32_t ParmTypeMask = 0xC000'0000;
380 
381   // Vector extension
382   static constexpr uint16_t NumberOfVRSavedMask = 0xFC00;
383   static constexpr uint16_t IsVRSavedOnStackMask = 0x0200;
384   static constexpr uint16_t HasVarArgsMask = 0x0100;
385   static constexpr uint8_t NumberOfVRSavedShift = 10;
386 
387   static constexpr uint16_t NumberOfVectorParmsMask = 0x00FE;
388   static constexpr uint16_t HasVMXInstructionMask = 0x0001;
389   static constexpr uint8_t NumberOfVectorParmsShift = 1;
390 
391   static constexpr uint32_t ParmTypeIsVectorCharBit = 0x0000'0000;
392   static constexpr uint32_t ParmTypeIsVectorShortBit = 0x4000'0000;
393   static constexpr uint32_t ParmTypeIsVectorIntBit = 0x8000'0000;
394   static constexpr uint32_t ParmTypeIsVectorFloatBit = 0xC000'0000;
395 
396   static constexpr uint8_t WidthOfParamType = 2;
397 };
398 
399 // Extended Traceback table flags.
400 enum ExtendedTBTableFlag : uint8_t {
401   TB_OS1 = 0x80,         ///< Reserved for OS use.
402   TB_RESERVED = 0x40,    ///< Reserved for compiler.
403   TB_SSP_CANARY = 0x20,  ///< stack smasher canary present on stack.
404   TB_OS2 = 0x10,         ///< Reserved for OS use.
405   TB_EH_INFO = 0x08,     ///< Exception handling info present.
406   TB_LONGTBTABLE2 = 0x01 ///< Additional tbtable extension exists.
407 };
408 
409 StringRef getNameForTracebackTableLanguageId(TracebackTable::LanguageID LangId);
410 SmallString<32> getExtendedTBTableFlagString(uint8_t Flag);
411 
412 struct CsectProperties {
CsectPropertiesCsectProperties413   CsectProperties(StorageMappingClass SMC, SymbolType ST)
414       : MappingClass(SMC), Type(ST) {}
415   StorageMappingClass MappingClass;
416   SymbolType Type;
417 };
418 
419 } // end namespace XCOFF
420 } // end namespace llvm
421 
422 #endif
423